Had an odd brake issue but solved - Just info

[1975 Kombi]

I had a front brake caliper hanging up on me. The rim was hot every time I came back from a trip. So I started tracing the problem. First the caliper bleeder was loosened and brake fluid shot out and released the caliper which moves freely when the pushing the cup while bleeder open. If the bleeder is closed it will not release the brake. I took apart the caliper and replaced - same thing. I replaced the caliper - same thing. OK not the caliper. Onto the the master and decided to reverse the lines just to see if there was any change in the behavior. Seemed to bleed ok and and tried it a bunch of times. So I went to the local shop and the first thing out of his mouth was rubber flex line. Apparently there has been a rash of inner rubber failure on rubber flex lines in the last few years. So changed up the relatively good looking flex line at least from the outside and sure enough the hang up disappeared. From what I gathered from the shop guy is that the inner portion of the hose cracks and flaps down to block off the fluid from returning. It starts to work as a one way check valve.
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Brett

“He’s decieving you boy! Reach into his pocket and take what he’s got.” Mr. Crabbs.

75 Westy auto
03 Jetta TDI
71 SB
74 Westy
Licensed pilot (single engine land VFR)
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Rust In Pieces: 72 Bug, 73 Bug, 81 Rabbit LS D 2D, 83 Rabbit D 2D, 84 Jetta TD GL, 85 Jetta D, 68 Z28 RS 302, 91 Passat 16v

[busdaddy]

[71whitewesty]

I just had the exact same experience. Replaced both front calipers and it ended up being the rubber hoses. You can also isolate that part by cracking the break line at the top of the rubber hose and see if it releases the caliper and if not try cracking the break line below the rubber hose. If it then releases, it's the rubber hose. Oh well, replacing the calipers too probably wasn't a bad idea.